Hearth for type founding and the like



June 5. 1928.

J. RABATE HEARTH FOR TYPE FOUNDING' AND THE LIKE Filed June 13 1927 7 2 Sheets-Sheet 2 H 4 M 23 24 Z? '35 5 I 37 as 4- I c- 1112-5112? 27 Patented'Jui'ie 5. 1928.

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Application 'nled i 1a, 1927, Serial llo. 19am, and in France June as, 1m 6 a My invention relates to type founding hearths and the like, especially to those adapted for the moulding of stereotype plates for rotary printing machines and par- 5 ticularly for newspaper printing machines which require the use of a comparatively great amount of metal in a comparatively short time.

v According to my invention the furnace l flames and gases after heating in a uniform manner the whole surface of the crucible pass over the metal bath under avault and then' into an exhaust pipe. Thus'the bath is not exposed to an excessive'cooling and the oil, 1 rosin and fat brought into the bath are burnt at about 500 0., their combustlon having for furtheradvantage the reduction of the slag.

' ,The vaultis preferably heat insulated.

In a preferred form of execution the space between the crucible and the refractory'lin- 'ing of the hearth is divided into several flues soas to obtain as long a distance as possible for the travel of the gases. For instance the gases may be caused to travel through two successive superposed The heating is improved by this feature and by. s'uitable regulating means to be disclosed hereinafter and the consequent lesser consumption of fuel allows a speedier melting -of the metal than heretofore and the bath need not in some cases be stirred at all. The vault only covers part of. the bath, the remainder. being covered by a flat cover. through which pass the metal suction/pipe and the stirring instruments when necessary.

. The two corresponding parts of the bath itself are separated by a,metal gauze disposed throughout its depth in view of separating I the partwhere the combustion of the impurities takes place and that wherefrom the metal is taken out.- y i A device is besides used for introducing the metal and old plates to be melted without allowing fresh air to enter with it, which would cool the bath. I

'My improved hearth keeps its heat for a long time provided the exhaust pipe "is closed. As oil burners have a greater efficiency at full load-,-f.it is preferable to use them fully open and to interrupt them, when necessary, the exhaust being simultaneously closed. V

On appended drawings I have shown by way ofexampletwo forms. of execution of 2 my inv ntion.

removing theslag from the top of the bath.

1, 2 and 3 are a vertical longitudinal section a vertical transversal section and a plan view of a first form of execution.

-F1gs. 4, 5 and 6 are similar views of a second form of execution. The crucible 15 is borne by a heat insulated metal frame 16 lined with a refractorymaterial. 1 In the middle of the vertical distance separating the edges of the crucible and the bottom of the frame are disposed two horizontal partitions 17, 18 so as to form a lower flue 10 extending under the whole len h of the crucible and two upper flues 20, 1 e nding on each side of the'crucible.

A burn 22 is disposed at the entrance of the lower crucible. The flames follow the path shown in dotted lines on Fig. 4. They pass through thelower flue and in the-opposite direction through thetop flues. The crucible I5 is closed by the vault 23 over a little more than half its length and by the I flat cover 24 over the remainder. The vault 23 is rovided with two pipes 25,26 the, ends of -w ich pass through the walls of the end of the hearth and open in the top flues20, 7 21. {This vault is also provided with an escape flue 27 which may be closed by a damper; 28. One of the sides of the vault 23 shows a door 29 for engaging a ladle and The opposite side of the vault is provided with a duct 30 for introducing the metal. This duct is slightly. sloping and its lower part is provided with'rollers 31'. It is closed by tivo doors 32, 33 hinged by their top edge to the duct and closing under the effect of their weight whilst bearing in a slanting position againstthesaid duct. A ledge 34' is disposed for receiving the-metal before its introduction into the hearth. A grid 35 divides the two parts 36, 37 of the bath corresponding. to the vault 23 and the cover 24. The stirring device, not shown, and a molten metal removing device 37' are disposed 1n part 37. I

The vault 23 and the whole of the hearth are carefully heat-insulated.

The hearth works in the following man a danger of breaking the crucible. The gases 119 metal disposed in the crucible -15, A

pass through the pipes 25,26 into the vault 23 and escape through the chimney 27. The gases in the vault 23 are at a temperature of about 500 C. The optimum temperature for the bath is 300 to 350 C. soon as the bath is molten the stirring device (not shown) is actuate and when the metal'has reached the desired temperature the metal is removed intothe molds. The addition offresh metal ingots or of plates is provided by disposing them on the ledge 34: and pushing them against the door 33 which 'rises and lets them pass. They move forwards over the rollers 31 up to the door 32 which they also raise before falling into the bath.

" As stated hereinabove, it is of advantage to throw the old plates-into the bath without cleanin them as usual heretofore. Under the infi uence of the temperature of 500 underthe vault 23", the oils and the rosin due a to the inking of the said plates burn on the surface of the bath under the vault and their reducing action together with that of the gases from the hearth diminishes the amount of slag forming on the surface of the bath.

Due tothe small deperdition of heat ina and the like comprising a crucible adapted furnacebuilt in the above described manner, the molten bath may be kept a lon time without becoming solid. It is there ore of advantage to allow the oil burner 22 to burn at full rate, the damper 28 being closed when the operation of the burner is stopped.

In a 9-ton.hearth of the above type the economy in fuel over the old types is more than 60%. The time necessary for themelt ing of a solid mass, filling the cruci leis only two hoursand the production 0 slag.

is reduced by 25%.- The results are even better when the burner. instead of bein disposed at the lower part of the arrangement is disposed above the bath level whereby the how of the gases is reversed as shownin dotted lines on Figs. 4, 5 and 6 where similar parts are shown by similar-reference numbers. In this modification theburner 22 is disposed at the end of the crucible and above the molten metallevel. The flames and gases are led therefrom into the hearth through the duct 22' and after passing over the bath return through 25 and 26 to the superposed flues through which they pass in the reverse direction to that showmon Figs. 1 to '3. Of coursethe exhaust flue 27 communicates on one hand with the end of the lower flues and ends on the other with the stock 27 disposed next to the metal feed device. Thus the vault over the crucible may be entirely closed.

An advantage of this arrangement resides in :fill whereby all danger of fire is avoided:

Moreover the fuel combustion is much reduced as the gases flow in a methodical direction which is opposite: to that of the precedent case and the amount of slags produced is much reduced.

What I claim is: 1

1. A hearth for stereotype plate founding and the like comprising a' crucible adapted to receive the plates and metal to be melted,

a burner, means for directing the flames and vprisinga series of horizontal flues wherethrough the flames and gases are ada ted to pass in succession round and below t e crucible.

'3. A hearth for stereotype plate founding to receivethe plates and metal to be melted,

a burner, means for directing the flames and the channel adapted to be opened by the metal and plates passing into the crucible,- a flat cover over the other part of the cru- 'cible and means for removing the molten metal from the part of the crucible covered by the flat cover.

4. A hearth for stereotype plate founding ,and the like comprising a crucible ada ted to receive the plates and metal to be me ted, a'gburner, a conduit connecting the burner with'the crucible above the metal level, ducts cible, a series of successive horizontal flues the first of which are connected. with the. said duct, a chimney connected with the last flue, a vertical grid dividing the crucible in -two parts, a vault over one part thereof, means for feeding the plates and metal into the part of the crucible covered by the vault, a flat cover over the other part of the cru-, cible, and means for removing the molten metal from the by the fiat cover.

In testimony where of' I have aflixed my signature k JEAN RABATE.

connected with the'upper part' of the cru-.

part of the crucible covered 

